Can I switch my SIP (HDFC Mid-Cap opportunity fund-growth) to ELSS or any other tax saving fund? I can see switch to different tax saving funds on the website, my confusion is that, if I convert my SIP to tax saving one, does it qualify for 80c?

You can switch current holdings from the HDFC Midcap fund to the ELSS fund. The amount switched will be counted towards Section 80C. Old SIP into midcap fund will continue unless you stop it.

When switching do ensure that you switch to a Direct Plan Mutual Fund in the ELSS category. Else you lose significantly to commissions upto 40% of the portfolio in the long run.